Hypertension, also called high blood pressure, is a condition in which the force of the blood against artery walls is elevated. Approximately one out of three adults in the United States has hypertension. This condition is a major cause of cardiovascular disease and often causes heart attacks, strokes, and kidney failure.
Systolic and diastolic are the terms used to describe the two values measured during a blood pressure reading. The systolic pressure is the force inside the arteries when the heart beats (pumps blood out to the arteries). The diastolic blood pressure is measured between beats, when the heart is at rest. Blood pressure readings are recorded with the systolic number written above the diastolic number, for example 110/70 mmHg. In medicine, the standard unit for measuring pressure is a millimeter of mercury (mmHg).
Frequently, the cause of hypertension is unknown; this form of hypertension is called essential hypertension or primary hypertension. When hypertension is caused by another medical condition - for example, kidney disease or thyroid disease - the term secondary hypertension is used. Additionally, some medications such as birth control pills, steroids, and over-the-counter cold medications elevate blood pressure.
Children and adolescents normally have lower blood pressures than adults, and the incidence of hypertension increases with age. Unfortunately, the incidence of pre-hypertension and hypertension is steadily increasing in children and teens because of the growing problem of childhood obesity.
Typically, people with hypertension do not experience any symptoms; therefore, many patients are unaware that they have a problem until complications arise. The only way to know whether hypertension is present is to measure it with a blood pressure gauge.
Untreated hypertension often leads to serious complications. High blood pressure damages arterial walls and promotes plaque accumulation, resulting in narrowing (stenosis) and hardening of the arteries throughout the body. Narrowing of the arteries leads to inadequate blood flow and damages organs.
Hypertension leads to the following complications:
A person’s blood pressure normally varies throughout the day and is usually lower during sleep and higher during periods of stress or activity. Because of this variability, blood pressure readings at two separate office visits help determine whether a patient’s usual blood pressures are high.
Usually, the goal of treatment is to reduce blood pressure to below 140/90. Because of the increased risk of complications in adults with coronary artery disease, diabetes, or chronic kidney disease, the treatment goal in these groups is a blood pressure below 130/80.
Hypertension is initially treated with lifestyle changes. However, in most cases, physicians recommend a combination of lifestyle changes and antihypertensive medications to control blood pressure.
Physicians may prescribe one or more medications based on a patient’s response to treatment, other medical problems, and tolerance of side effects.
Generally, high blood pressure is a lifelong condition that requires ongoing treatment after the blood pressure is under control. Because hypertension is asymptomatic, many patients do not properly adhere to their treatment regimens, making the condition difficult to control.
In many cases, hypertension is preventable with lifestyle factors, such as:
In addition, early treatment of patients with prehypertension or hypertension reduces the risk of cardiovascular complications.